Low-Cost Hinge for Deployable Structures

This report presents a study of a recently proposed low-cost hinge for deployable spacecraft appendages. The hinge consists of one or more pairs of steel carpenter tapes (tape springs) connected to a rolling hinge made from plastic " wheels " connected by steel cables (Rolamite). This hinge is known as Tape-Spring Rolamite (TSR) hinge. The report includes: a brief review of the relevant background to TSR hinges; a study of the moment-rotation relationship of TSR hinges; parametric relationships between key values of the moment-rotation relationship in terms of key design parameters, leading to the design of an improved hinge that is better suited for most practical applications; an extensive experimental study of the stiffness of a TSR hinge in the deployed state, backed by simple analytical predictions that are shown to be reasonably accurate for design purposes; analytical stiffness predictions in the deployed configuration; and deployment experiments on lightweight sandwich panels connected by TSR hinges, with an assessment of the performance of different damping mechanisms. The key achievements of this study are: (i) experimental stiffness data for TSR hinges, (ii) experimentally validated analytical methods for predicting stiffness ; (iii) detailed finite-element simulations of the folding/unfolding process; (iv) improved hinge design; and (v) assessment of passive damping methods for reducing end shock.